Cooperative Study for the Clinical Comparison of LAAM and Methadone patients as per protocol for additional 40 weeks - see attached protocol. In addition, an evaluation of LAAM in women of non-child- bearing potential. Applicants for this modification will be limited to: (1) Females with verified history of hysterectomies. (2) Females with verified tubal ligations. (3) Post-menopausal females having no menstruations for at least one year. (4) Females with verified sterility from other medical causes, e.g., bilateral oophorectomies or sterility from primary amenorrheas. All of the procedures of the parent study will be followed with the exception of those sections relating to random assignment of patients to treatment. Because of the limited number of women meeting the eligibility requirements, all women that agree to be in the study and sign the informed consent will be assigned to LAAM. They should be told that if they agree to participate they will receive LAAM. For every woman started on LAAM, a female methadone control should also be started. Any female who satisfies the requirements of the male protocol is a candidate including sterile women who do not want to receive LAAM. From this pool of candidates, a methadone control patient should be selected who is roughly comparable to the LAAM patient in terms of age, duration of addiction to opiates and length of methadone maintenance. Rather than set precise limits on these variables, e.g. plus or minus five years for age, it is suggested that the best match possible be made in each instance.